Threats

Green sturgeon populations successfully persisted throughout North America for two-hundred million years, but are thought to have experienced a precipitous decline during the past century. Harvest of adults likely resulted in direct declines in abundance, and destruction of spawning and rearing habitats led to reduced populations sizes and resilience. With regulations prohibiting harvest or take now in effect, the most significant threats to green sturgeon likely relate to loss and inaccessibility of available spawning habitat. Much of this is driven by competing water resource needs between humans and fish.

Temporary dams, altered flows, and entrainment in water diversions can impede or inhibit both upstream spawning migrations of adult green sturgeon and downstream migrations of juveniles. Insufficient freshwater flow rates in spawning areas, containments, fisheries bycatch, poaching, invasive species, impassable barriers, and unfavorable water conditions are also likely to threaten the survival and recovery of this ancient fish.